“I think one of the things that’s struck me over the years is, the way communities have segregated, it’s easy to be in a bubble,” said Greene, a Newton resident.

On Sunday from 4 to 7 p.m., Greene will hold a fund-raiser at her home
for the Union of Minority Neighborhoods, a Jamaica Plain nonprofit organization with a mission of helping leaders of color to organize and work on issues of concern in their community. Former governor Michael Dukakis, a longtime supporter of the organization, will make an appearance at the event.

Greene said she was attracted to the group’s emphasis on empowering people within their own communities, but she also hopes the event will help create ties between Newton and neighborhoods of color in Boston.

“This is all about expanding our idea of neighborhood,” she said. “Can we be allies to one another beyond the borders of our communities?”

That mission seems even more vital as Boston and its neighbors mourn together over the lives lost in the bombing attacks Monday at the finish line of the Boston Marathon.

“It reminds us that we’re all in this together,” Greene said. “We’re all impacted regardless of our race or class or culture. We’re going to carry on and do this event. This is going to be a gathering that recognizes the importance of unifying and coming together as communities and helping each other out.”

Greene only recently became a supporter of the group. But Horace Small, executive director of the Union of Minority Neighborhoods, said a core group of Newton residents has been helping the organization since its inception in 2001, with at least three currently sitting on the group’s nine-member board of directors.

“I don’t know what it is about Newton,” said Small. “It just seems like the progressive community, the active participants in the fight for social justice, are the folks who come out of Newton. We’ve all become great friends.”

Small said the organization works to develop leaders so they can tackle grass-roots initiatives on their own, and it has worked for improvements in public education and the criminal justice system.

The Union of Minority Neighborhoods is leading a project to open up a public conversation about Boston’s desegregation busing crisis of the 1970s. The project grew out of its attempt to organize people around public education. Small said he found that some people didn’t “buy” the idea that public education could solve problems in their communities.

“They stopped believing that with busing,” Small said, “and that generation is the parents and the grandparents” of current students.

Small said the issue is “touchy” among some who would rather leave it in the past, but he said Boston’s reputation as a place that’s hostile to diversity lingers for many.

“We still live in a city where you can’t get quality black and brown people to come here for leadership positions, because they think this place is as racist as the day is long,” Small said.

“You cannot become a world-class city until you address the issues that happened in the past,” he said.

Joe Leavey, one of the Newton residents on Small’s board, and who is president of another Boston nonprofit organization, said his city’s connection with the Union of Minority Neighborhoods isn’t the result of a coordinated effort.

“Part of it is just coincidence, but I think Newton does have a lot of residents that are concerned about trying to help out an agency like the union,” Leavey said. “They’re doing some very important work, and I think we look at it as the more people who feel disenfranchised, the more they get involved and realize they do have some power, the better things are going to be for Boston.”

“It’s the world we live in. It’s becoming a smaller place,” said Tracy Miller, another Newton resident on the group’s board. “Our kids are seeing things more quickly, learning things, and I think it’s important for that connection to be there, the connection to Boston, to the people in Boston, and to understand that it’s not that far away.

“It hasn’t happened so much, but I feel like this is a tremendous opportunity for us to turn that corner,” Miller said of the event Sunday being hosted by Josie Greene. “I feel like this is a very, very good opportunity to make that connection.”